Which MacBook Pro for d800?

I need to upgrade my laptop to process the large files and given that we are largely Apple converts am considering a MacBook 13 Retina with 8MB RAM following the drop in price. I intend to use Aperture and possibly Lightroom 4. I am not a pro and my experience in processing RAW files is limited. I am concerned whether 8mb RAM with the flash drive is sufficient to work with the large files produced by the D800 as no upgrades are possible. I will use external storage as back-up. Looking for peoples experience with this device. Cheers S